As technology for selectively separating and collecting gas containing plural kinds of gases or specific gases represented by a CO2 gas, a variety of methods such as, for example, an alkanolamine method, a membrane separation method, and a chemical absorption method have been already made available. Recently, from the viewpoint of preventing global warming, technologies have been developed for collecting and removing CO2 gas effectively from the exhaust gas emitted from facilities such as incinerators, and power plants.
Although the alkanolamine method (see, for example, Japanese Patent Application Laid-Open No. 7-100334) represented by a scrubber is easy to develop on a large scale, and its use has become increasingly widespread, a problem exists insofar as there is a substantial loss of energy in the reproduction of a gas absorption liquid for use, and accordingly the quality of the gas absorption liquid deteriorates to a significant degree. Further, the membrane separation method gives rise to a problem insofar as the membrane is expensive and its rate of gas collection is low. Moreover, the chemical absorption method entails a problem insofar as the absorption member made of a material like ceramics deteriorates easily, and the service life of the absorption member is correspondingly short.
Accordingly, an object of the present invention is to provide a gas collection method and an apparatus that is capable of collecting specific gases from gas to be processed effectively, in a high concentrations with a modest loss of energy, a method and an apparatus that can further be applied widely to a variety of apparatuses ranging from small to large scales.